Gas-testing apparatus



G. G. OBERFELL AND A. M. BALLARD.

GAS TESTING APPARATUS. APPLICATION FILED APR. 27, 1920.

Patented Oct. 25, 1921.

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GAS TESTING APPARATUS.

APPLICATION FILED APR. 27, I920.

Patented 0011. 25, 1921.

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UNITED STATES PATENT OFFICE GEORGE G. OBERFELL AND ALBERT M. BALLARD, OF TULSA, OKLAHOMA.-

e s-rnsrms APPARATUS.

To all whom it may concern Be it known that we, GEORGE G. OBERFELL and ALBERT M. BALLARD, citizens of the United States, residing at Tulsa, 1n the county of Tulsa and State of Oklahoma, have invented certain new and useful Improvements in Gas-Testing Apparatus; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in the methods and apparatus for testing gaseous mixtures.

A knowledge of the static and dynamic pressure of the gas and the density of the gas is required in determining the flow of gas from gas Wells or from Oll wells. The apparatus herein described'was developed for use in connection with such tests and tests of similar nature.

Since a knowledge of the densit of natural gas affords a rough idea of t e gasolene content and heating value of the gas, the apparatus may be used for such purposes preliminary to testing the gas by an accurate method of analysis.-

The object of the present invention is to provide improved methods and apparatus for the above purpose and to furnish an apparatus that is more compact and portable, more readily and economically constructed and operated, and is less fragile than any other apparatus known.

With the foregoing object outlined and with other objects in.view, which Wlll appear as the description proceeds, the invention consists in the novel methods and apparatus hereafter described in connection with the accompanying drawings, and more particularly pointed out in the appended claims.

Referring to the drawings Figure 1 is a front view of the apparatus with the front door in open position.

Fig. 2 is a vertical sectional view taken on line- 22 of Fig. 1. In this view the front door is closed and certain of the parts are removed.

Fig. 3 is a rear view of the apparatus with Specification of Letters Patent.

Application filed April 27,

Patented Oct. 25, 1921. 1920. Serial a... 377,029.

which has a bottom 2, side walls 3 and 4, a top cover 7, a front door 5 and a rear door 6.

Extending across the interior of the casingis a partition plate 8 having angular edge portions 9 which are secured to the bottom and side walls and hold the bottom and side walls together. A stay bar 10 extends across the upper portion of the easmg and its ends 11 are also secured to the side walls.

The top cover 7 is hinged at 12 to the side wall 3 and in normal position its free edge rests on a flange 13 provided at the upper end of the sidewall 4. The doors 5 and 6 oil, alcohol or water. The liquid bodies cooperate with suitable scales 20 and 21.

Secured to the leg 22 of the manometer 16 is a hollow metal fitting 23, which places the interior of the leg in communication with the interior of a pipe 24. A similar fitting 25 is connected to the leg 26 of the manometer 17 and places the interior of this leg in communication with the pipe 24. Needle valves 27 and 28 are provided for closing the passages 29 and 30, which extend from said pipe.

The legs 31 and 32 of the manometers are provided with removable plugs 33 and 34 which normally function to hold the liquid bodies in the manometers.

The pipe 24 has three vertically extending members 35, 36 and 37, two of which form casings for the needle valves and the other of which is hollow and provided with an end closure 38 having an aperture 39. These members project through apertures in the plate 10, and nuts 40 secure the same in place. A screw cover or cap 41 functions to close the aperture 39.

A branch 42 extends rearwardly from the pipe 24 and an L-shaped tube 43 is connected to said branch and carries a three-way fitting as. One of the legs of this fitting is connected by tubing 45 to an air pump 46. The other leg of said fitting 15 connected by tubing 45 to a flexible gas container 47.

The ends of the pipe as are closed by plugs elt f'ivhich may be removed when it is desired to clean the interior of said pipe.

The pump $6 in the present instance s shown as a rubber hand blower and this blower is used for compressing gas from about atmospheric pressure, or pressure somewhat less than atmospheric, to several pounds above atmospheric.

The gas container 4:7 18 preferably an elastic bag and it is used as 'a reservoir for gas or air. The bag is preferably formed of rubber protected by a casing of some durable pliable material, such as leather. The easing prevents sudden changes of temperature of the gas within the bag during tests.

To determine the specific gravity of density of a gas or gaseous mixture with the present apparatus, the method stated herelnafter is carried out.

The valve 27 is closed, the plugs 33, 34 and the cap 41 are removed and the valve 28 1s opened. The aperture 39 is then closed by the finger of the operator.

The pump 46 is then operated to force an into the bag 47. As the air pressure in the bag increases, the liquid in the leg 32 of the manometer 17, rises until the desired pressure is indicated on the scale 21. .A pinch clamp 49 on the tubing 45 is then closed, and the finger of the operator is quickly removed from the aperture 39. The escape of air through said aperture causes a drop in pressure within the bag and this pressure drop is indicated by the fall of the mercury column in the manometer 17. After the pressure has dropped to a point where it is not great enough to force the li aid from the manometer 16, the valve 27 is opened. The pressure drop is then readily observed by watching the fall of liquid in the manometer 16.

The time required for any definite decrease in pressure of gas within the bag is taken by means of a stop watch. This is done by starting the watch as the meniscus of the mercury 19 passes a fixed point on the scale 21 and stopping the watch as the meniscus of the light liquid 18 passes any fixed point on the scale 20.

The bag 47 is then purged of air. This may be done by forcing gas whose density is desired into the bag and then allowing the gas to escape therefrom. By repeating this process a few times, the bag will be free from air. The bag may also be purged by connecting the suction end of the hand blower to the apparatus, closing aperture 39 and putting a reduced pressure on the bag. The bag is then filled with gas whose density is desired, by means of the pump i6 01' by attaching the tubing 45 to a. suitable connection on the gas supply providing said gas supply exists under sufficient pressure. be time is then again noted in lme units for a pressure drop equal to that used with air. The specific gravity is calculated as follows:

(gas time) 2 (air time) 2 For example if it were determined that the time for pressure dro of gas was 80 seconds and that the time or pressure drop of air was 100 seconds, the specific gravity, or density, of the gas would be, therefore, 0.64.

The combination of a mercury gage and a light liquid gage permits of the readin of a wide range of pressure with a small helght for the manometer, and makes possible a sensitive method for timing pressure drop.

The flow of the gas may be determined by means of the orifice meter or Pitot tube by methods readily understood by those skilled in the art. The manometers 16 and 17 may be used for noting the pressure as is required in such tests.

We are aware that several changes may be made in the design, construction and operation of an, apparatus such as we have described without departing from the spirit of this invention. For example, the apparatus may be successfully used with one manometer. The time required for any definite decrease in pressure of gaswithin the bag is determined by timing the pressure drop by the fixed limits on the scale of the one manometer only. The apparatus may also be so constructed as to feed most of the gas through the orifice under a constant pressure. We have found that apparatus having such modifications do not give results of greater accuracy, and are more difiicult to operate.

What we claim and desire to secure by Letters Patent is 1. A method of testin a gaseous mixture to determine the specific gravity of said mixture, which method consists of forcing air and gas alternately into a chamber, placing the air and gas alternately under pressure, allowing the gas or air in the chamber to escape through an orifice, indicating the decreases in pressure within the chamber as the gas or air escapes, noting the time re" quired for dissipation of said gas or air pressure between desired pressure limits, and calculating the specific gravity from the relation between the times required for dissipation of gaseous mixture pressure and dissipation of air mixture pressure through the same ressure limits.

2. n a method of determining the specific gravity of a gaseous mixture, the steps of alternately placing air or the gaseous mixture in containing means, compressing the Specific gravity air or gaseous mixture to a predetermined degree, permitting the air or gaseous mixture to escape from the containing means through an aperture to reduce the pressure by the same amount for both the air and gas, and noting the difference in time required to permit the exit of the air or gaseous mixture through the aperture to reduce the pressure Within the containing means.

3. In a method of determining the specific gravity of a gaseous mixture, the steps of placing air in a containing means, compressing the air to a desired degree, permitting the air to escape from the containing means through an aperture, timing the period required for permitting the pressure of the air to fall a desired degree, placing a compressed gaseous mixture in said containing means and permitting the escape of said gaseous mixture through said aperture, noting the time required for pressure of the gaseous mixture to drop equal to the pressure drop of the air, and calculating the density or gravity of the gaseous mixture from the perlods of time required for the pressure drops.

4.. A gas testing apparatus including a container for gas or air, a plurality of manometers communicating with said container, one of said manometers containing a heavier liquid than the other manometer, for forcing air under pressure into said container, and means for closing the communication between the container and either of said manometers, and means for permitting the exit of air or gas from said container.

5. An apparatus as defined in claim 4 in which the communication closin means includes a manually controlled va ve.

6. A gas testing apparatus comprising a pipe, a plurality of manometers connected to said pipe and normally communicating with the interior of the same, means for closing communication between the pipe and manometers, a two branched tube extending from said pipe, a container for air or gas having its interior communicating with one branch of said tube, an air pump connected to the other branch of said tube, and means providing a restricted orifice for permitting the escape of air or gas from said container.

7. An apparatus as defined by claim 6 in which the liquid of one manometer is heavier than the liquid of the other manometer.

8. A gas testing apparatus comprising a casing having front and rear doors, a partition dividin the interior of the casing into a plurality o compartments, a pipe, a plurality of manometers connected to said pipe and located in one of said compartments, a

container for air or gas and an air pump located in the other compartment, means connecting the container and pump to the pipe, and means for permitting the exit of air or gas from said container.

9. An apparatus as defined in claim 8 in which means are provided for closing communication between the manometers and GEORGE G. OBERFELL. ALBERT M. BALLARD. 

